The present invention relates to a technology which can determine the order of execution for jobs in an image forming apparatus such as, for example, a copying machine and a printer.
There has been developed a digital copying machine which reads a document to store it as image data, and can make hard copies based on the image data. In the so-called multi-job copying machine which is one type of the digital copying machine stated above, plural documents are read at a time, then, they are recognized as hard copy jobs for each document, and hard copies are made in accordance with the order of execution.
Incidentally, one of merits of the multi-job copying machine is a point that a user can change the order of execution for jobs freely. For example, in a multi-job copying machine, hard copies are made usually in the order of reading documents. However, when there is a job which requires a hard copy urgently, a user can operate a reservation list of jobs so that the job requiring a hard copy urgently may be moved to the forefront of the reservation list. By doing the operation of this kind, it is possible to execute the specific job only on priority basis.
However, operations of the reservation list have the following problems. A multi-job copying machine is usually used by plural users, and each user does not know the degree of urgency for hard copies desired by other users in many cases. Therefore, there is a fear that a job whose degree of urgency is higher is put off when a certain user gives a priority to his job through operations of the reservation list.
Further, since procedures of the operations of the reservation list are complicated, operations require a certain level of experience. A user who is inexperienced in the operations, therefore, needs to be told by other users who are skilled in the operations about procedures to give priority to the job. However, in many cases, execution of the job is undesirably finished while the operations for the job are told, and the operation procedures told are sometimes forgotten before they become necessary again next time.
Further, for a user who thinks it very troublesome to learn operation procedures, it is presumed that the user can not give priority to its own job and the job is put off by operations of other users, even when a hard copy is needed urgently, resulting in a considerable period of time for which the user must wait.
On the other hand, in the multi-job copying machine of this kind, it is also possible to use an interruption job function to stop the active job by force and to execute the specific job antecedently. However, in the active job, when the specific finishing such as stapling is executed, there is provided a mechanical restriction to prohibit the same finishing for the job of interruption, for preventing confusion.